Comment 8 for bug 1914740

Thx Alexandra and Asha for digging deeply into that issue with the hipersocket environment.
So the initial reason was to use L3 because of potentially connecting to z/OS instances?

And yes, isc-dhcp-client is Ubuntu's (and I think also Debian's) preference (for quite some time).

I think using "bootp-broadcast-always" is a conf option that works at least down to 4.2.x (but possibly even earlier).
I understand that an arg for the client would be nicer.
Well, you mentioned that isc-dhclient-4.4.2 will probably ship with such an option that allows to instruct the DHCP server to broadcast the response back to the client?
May I ask where you've read that?
I'm asking because I found that 4.4.2 got just released end of January: https://www.isc.org/dhcp/
And the 21.04 feature freeze is on the 25th Feb, so there is a little chance to get that in.
But I couldn't find anything in the 4.4.2 tar ball about such an option (well, maybe it got simply delayed or so ...)

Btw. I guess the Device Drivers guides were recently moved to a new location (since the URL you pointed to didn't had the Ubuntu 20.04.1 version, that puzzled me a bit).
I think it's now at the 'IBM Knowledge Center' (and no longer on devWorks):
https://www.ibm.com/support/knowledgecenter/linuxonibm/liaaf/lnz_r_ubuntu.html
the Ubuntu 20.04.1 flavor of the Device Drivers guide here:
https://www.ibm.com/support/knowledgecenter/linuxonibm/liaaf/lnz_r_u2004.html

And I totally agree to use interfaces in L2 mode whereever possible, especially when it comes to DHCP. And so far I only saw DHCP environments on Z in L2 mode, hence my surprise at the very beginning about the combination of DHCP / Hipersockets / L3.